Williams syndrome (WS) is a rare genetic disorder that results from a deletion in the region q11.23 of chromosome 7. Individuals with Williams Syndrome have a characteristic facial appearance, severely impaired visuospatial skills, relative preservation of language skills (typically in concrete, practical vocabulary, as opposed to abstract vocabulary), and a highly social demeanor. In contrast, individuals with autism have notable impairments in social interaction abilities. Thus, these two developmental disorders have quite opposite effects on social behaviors, and comparative studies may illuminate many aspects of social cognition (Tager-Flusberg et al., 2006).

A number of previous studies have examined the patterns of eye gaze while participants with autism view pictures of human faces (e.g., Sasson et al., 2007), but no experiments to date have applied the same techniques to WS. Riby and Hancock (2008) tested 16 people with WS (ages 8-28, mean age 17.5 yrs) and 20 people with autism (ages 6-18 years, mean age 13 yrs). A control group of typically developing children and adults with low nonverbal scores (ages 8-28, mean age 17.5 yrs), and groups of age-controls were formed for comparison.

The participants viewed 20 pictures of social scenes and 5 filler photographs for 5 sec each while gaze was monitored with an eye tracker. Fixation "areas of interest" (AOI) were designated, and included face (eyes and mouth), body, and background. The results are illustrated below.

Fig. 1 (Riby & Hancock, 2008). Fixation duration as a function of group membership. Hotspots represent the relative amount of time spent fixating throughout the scene for each group (a) typically developing children, (b) autism and (c) WS.

There was a statistically significant interaction between AOI and group. The WS subjects viewed faces for a longer duration than did their respective controls. Specifically, the WS group spent more time viewing the eyes, but not the mouth. Conversely, as has been demonstrated in previous studies, the participants with autism spent significantly less time looking at faces (eyes in particular) than did their controls.

Whilst individuals with autism spent a significantly smaller proportion of time than typical fixating on characters’ eyes (17% of face gaze time), those with WS spent significantly longer than typical fixating on the same region (58% of face gaze time). Visual attention to the eyes may be implicated in other divergent abilities in face perception, such as the interpretation of gaze cues and expressions, where individuals with WS are more proficient than those with autism.

The authors suggest that future research should focus on the causes of atypical social preferences in WS (e.g., differences in amygdala and prefrontal cortex function relative to controls).

Footnote

1 The authors are not responsible for that title, which is not meant to be offensive.

The genetic disorder Williams syndrome (WS) is associated with a propulsion towards social stimuli and interactions with people. In contrast, the neuro-developmental disorder autism is characterised by social withdrawal and lack of interest in socially relevant information. Using eye-tracking techniques we investigate how individuals with these two neuro-developmental disorders associated with distinct social characteristics view scenes containing people. The way individuals with these disorders view social stimuli may impact upon successful social interactions and communication. Whilst individuals with autism spend less time than is typical viewing people and faces in static pictures of social interactions, the opposite is apparent for those with WS whereby exaggerated fixations are prevalent towards the eyes. The results suggest more attention should be drawn towards understanding the implications of atypical social preferences in WS, in the same way that attention has been drawn to the social deficits associated with autism.

A recent neuroimaging study (An et al., 2008) used a symptom provocation procedure to examine the neural correlates of hoarding. The research participants were restricted to individuals with obsessive-compulsive disorder; those hoarders without an OCD diagnosis were excluded. Thus, two groups of OCD patients (those with and without hoarding symptoms) were compared to demographically matched controls while viewing three types of pictures [the figure is my completely fabricated rendition of possible exemplars2].

(2) aversive control - 50 color pictures of scenes rated as highly disgusting and anxiety-provoking by healthy subjects were also obtained from the IAPS. These included scenes of mutilated bodies/wounds, small animals (snakes, spiders, cockroaches and rats) and body products.

(3) commonly hoarded objects - 50 color pictures that included items such as old magazines/newspapers, empty food containers, clothes and toys. These pictures were rated by several patients (not in the fMRI study) to ensure that they would be anxiety-provoking.

The pictures were presented in alternating blocks of neutral and emotional. Participants were instructed to

imagine being in a particular situation while looking at the scenes they were about to see (for example, for hoarding: ‘Imagine that these objects belong to you and that you must throw them away forever;’ for aversive control: ‘Imagine that you must come into contact with what is shown in the pictures’). After each set of pictures were presented, another prerecorded sound file of the question ‘How anxious do you feel?’ was played and the subjects rated their subjective anxiety on a Likert-style scale (0 = no anxiety to 8 = extreme anxiety).

Not surprisingly, the OCD-hoarders rated the hoarding pictures as more anxiety-provoking than did the other two groups. However, the aversive control pictures were rated as equivalently yucky by all three groups.

What did the fMRI results show? From the previous neurological case studies, one would expect differences in the orbitofrontal cortex of the OCD-hoarding group, relative to the non-hoarding and control participants. And indeed, when viewing the provocative stacks of magazines and empty food containers,

Figure 2A (An et al., 2008). Brain regions significantly more activated in hoarders than in non-hoarders and controls (shown in red) during symptom provocation. The functional data are superimposed on a high-resolution anatomical template using the MRIcro software. The left side of the brain appears on the right side of the image. The box plots depict the percent change in blood oxygen level dependent (BOLD) response in each group. In each box plot, the horizontal lines represent the group median, the box represents the quartiles and the whiskers the extreme values in each group.

In contrast, when comparing the disgusting aversive pictures to neutral pictures, the activated regions in the hoarding OCD patients were more similar to those that were seen in the non-hoarding OCD patients and the healthy control participants. However, the hoarders did show less activation in the cerebellum and visual areas than the controls (and the non-hoarders showed more).

The authors suggest that

The brain regions associated with compulsive hoarding in this study are anatomically very close to those associated with hoarding behaviors ... in human lesion studies. Although it is plausible that hoarding behaviors caused by brain lesions may be phenomenologically and etiologically distinct from obsessive-compulsive hoarding, our results seem to suggest that they share similar neural substrates.

[Although the regions are missing in the human lesion patients, and overactive in the OCD hoarding patients...]

Several months ago, Mind Hacks reviewed the short documentary film, Possessed, which is about four people with compulsive hoarding disorder. The filmmaker, Martin Hampton, is currently working on a follow-up project about people's personal experiences with OCD.

Overall, the phenomenology of hoarding behavior was similar in the two hoarding groups [OCD with Hoarding, Hoarding only]. The majority of participants in both groups reported hoarding common items as a result of their emotional and/or intrinsic value. However, approximately one-fourth of participants in the compulsive hoarding with OCD group showed a different psychopathological profile, which was characterized by the hoarding of bizarre items and the presence of other obsessions and compulsions related to their hoarding, such as fear of catastrophic consequences, the need to perform checking rituals, and the need to perform mental compulsions before discarding any item. ... In most individuals, compulsive hoarding appears to be a syndrome separate from OCD, which is associated with substantial levels of disability and social isolation. However, in other individuals, compulsive hoarding may be considered a symptom of OCD and has unique clinical features.

2 I decided to use a moldy slice of bread, rather than a mutilated body part, so as not to offend the sensibilities of the more delicate reader.

Preliminary neuroimaging studies suggest that patients with the 'compulsive hoarding syndrome' may be a neurobiologically distinct variant of obsessive-compulsive disorder (OCD) but further research is needed. A total of 29 OCD patients (13 with and 16 without prominent hoarding symptoms) and 21 healthy controls of both sexes participated in two functional magnetic resonance imaging experiments consisting of the provocation of hoarding-related and symptom-unrelated (aversive control) anxiety. In response to the hoarding-related (but not symptom-unrelated) anxiety provocation, OCD patients with prominent hoarding symptoms showed greater activation in bilateral anterior ventromedial prefrontal cortex (VMPFC) than patients without hoarding symptoms and healthy controls. In the entire patient group (n=29), provoked anxiety was positively correlated with activation in a frontolimbic network that included the anterior VMPFC, medial temporal structures, thalamus and sensorimotor cortex. Negative correlations were observed in the left dorsal anterior cingulate gyrus, bilateral temporal cortex, bilateral dorsolateral/medial prefrontal regions, basal ganglia and parieto-occipital regions. These results were independent from the effects of age, sex, level of education, state anxiety, depression, comorbidity and use of medication. The findings are consistent with the animal and lesion literature and several landmark clinical features of compulsive hoarding, particularly decision-making difficulties. Whether the results are generalizable to hoarders who do not meet criteria for OCD remains to be investigated.

Saturday, July 19, 2008

In our second case study of "forced collectionism" caused by an acquired injury to the orbitofrontal cortex, a 49 year old man started collecting an unwieldy number of televisions and other household appliances (Volle et al., 2002):

A 40-year-old-man underwent surgical resection of an olfactory meningioma in 1988. He remained disease free until 1993, when the tumor recurred. He underwent surgery again in 1995. The postoperative CT scan showed two large porencephalic frontal defects with no tumor residue.

The pathologic collecting behavior was first noticed in 1997, when he began searching out domestic appliances such as television sets, telephones, refrigerators, vacuum cleaners, washing machines, or videocassette recorders. He developed logical and efficient strategies to get what he wanted. Twice a month, he roamed the town and brought appliances, mainly television sets, back home. He stocked them first in his living room, but when 35 television sets were stored there, he placed additional televisions in his daughter’s bedroom, then in the corridors, in the bathroom, and in his three cellars. In the end, when there was no empty space left in the cellars, he put them in ventilation shafts.

Unlike the collector of toy bullets from our first case study, the television man did not show significant impairments in memory and executive functions. In contrast, he showed a great deal of inertia in his everyday life (except when it came to collecting TVs). Notably, he was missing an enormous chunk of his frontal lobes bilaterally, as illustrated in the figure below.

On the left, the lesion extended over the anterior two-thirds of the superior frontal gyrus and the anterior third of the medial frontal gyrus. On the right, the lesion involved the anterior third of the superior frontal gyrus and a larger part of the medial frontal gyrus. A PET scan revealed bilateral orbitofrontal hypometabolism.

Although these unusual case reports do appear in the neurological literature, compulsive hoarding or collecting is much more common in psychiatric settings, as a disorder that may occur as a symptom of OCD (or as a separate diagnosis).

A previously healthy 46 year old man experienced a ruptured aneurysm of the anterior communicating artery, resulting in extensive damage to the left orbitofrontal cortex and caudate nucleus (Hahm et al., 2001). He underwent surgical procedures to remove the aneurysm and to shunt the buildup of excessive CSF, which was causing hydrocephalus. Two months later, he recovered his health but showed residual memory deficits and a number of behavioral changes, foremost among which was a newly-developed compulsion to collect an unusual item (and only that item).

The most interesting behavior began in July 1997 during his first walk in a park since his illness; his wife witnessed him picking up bullets of a toy gun from the ground. Thereafter, whenever he went outside, he walked with his gaze downward in search of these bullets. The plastic bullet was round and small (5 mm in diameter) (figure 1) and would be very challenging for most individuals to find in public. Nevertheless, he has collected over 5,000 bullets in the ensuing 2 years and kept them in bottles at home.

At home with his wife, he would not seek the objects. When left alone, however, he would wander the streets for hours, collecting bullets even in foul weather. Although his collecting behavior embarrassed his wife, he was unconcerned about the thoughts of others. He never collected other items besides the toy bullets.

Other papers (e.g., Anderson et al., 2005) have reported on the emergence of obsessive-compulsive, collecting, or hoarding behaviors following damage to the orbitofrontal region, but this is the first case of compulsive collecting of toy bullets.

Friday, July 18, 2008

A recent post in BRAINETHICS spawned an interesting discussion about the limits (and truthiness) of image coregistration. Thomas Zoëga Ramsøy spotted an egregious error in an fMRI study that appeared in a high-profile publication last year:

Take a look at this image. It’s from a 2007 article in Science by Depue et al.

It’s supposed to show activation in the hippocampus and amygdala. Looks innocent, right? Let’s take a closer look.

Since this paper was the subject of The Neurocritic's entry I Forgot... from July 16, 2007, it was time for me to take a closer look as well, since I missed it the first time around.

from Fig. 2C (Depue et al., 2007). Functional activation of brain areas involved in memory processes and emotional components of memory. Blue indicates greater activity for Think trials than for No-Think trials. Conjunction analyses revealed that areas seen in blue are the culmination of increased activity for T trials above baseline as well as decreased activity of NT trials below baseline.

In brief, this figure is supposed to illustrate that the hippocampus showed less activation when subjects were instructed to prevent the memory of a previously presented image from reaching consciousness. The authors (Depue et al., 2007)

used the Think/No-Think paradigm (T/NT) of Anderson and colleagues, in which individuals attempt to elaborate a memory by repetitively thinking of it (T condition) or to suppress a memory by repetitively not letting it enter consciousness (NT condition).

However, the blue blobs are outside the hippocampus, which is labelled in yellow.

I spent quite a while figuring the figues out. Did the yellow names indicate the blobs or where the structures actually are? For one thing, the blue blobs don’t fit into amygdala or hippocampus, but rather the entorhinal cortex.

First, the hippocampus is not present on this slice, so why put the name there? And why put it that lateral? This is really bothering. Do the researchers (and reviewers) really think that the hippocampus has anything to do here?

Second, the rightmost activation blob is centered in white matter. Hmm.. would that not give you the opportunity to speculate whether your coregistration was correct? I would.

I think you’re getting all worked up over very little. The slices shown range from y=-22 to y=5, so the clusters of activation probably extends beyond the hippocampus to include some other regions. It is rather weird that they would choose to label something clearly outside of hippocampus as such. Entorhinal cortex is part of the hippocampal system, so there’s nothing wrong with the “hippocampus” label.

IMO, too many people make fMRI localization in a much too loosely or unconstrained way. What do they do with these kind of activations? Use the SPM Anatomy toolbox… which definitely is wrong in this region. Or just the use of spatial normalization is known to induce errors.

. . .

So you get the anatomy wrong. What you call the hippocampus may be the entorhinal or perirhinal, what you call the amygdala may the the temporopolar cortex. So what, right? Isn’t this just one big system? Just as Squire, Zola and the others have claimed a long time ago? Well, if you look at the literature, there is a big discussion (just as ardent as that of the fusiform face area) that is vigorously debating the role of different medial temporal lobe structures. That is why this is important. It DOES matter what you label your blobs as, and in particular whether you check your images properly. People are way too sloppy about this (still).

Thursday, July 17, 2008

"Well, I know it was the New Yorker's attempt at satire," Obama told Larry King. "I don't think they were entirely successful with it. But you know what, it's a cartoon, Larry, and that's why we've got the First Amendment. And I think the American people are probably spending a little more time worrying about what's happening with the banking system and the housing market, and what's happening in Iraq and Afghanistan, than a cartoon. So I haven't spent a lot of time thinking about it."

Friday, July 11, 2008

ABSTRACT—Scholars have recently begun to harness the immense power of speed-dating procedures to achieve important and novel insights into the dynamics of romantic attraction. Speed-dating procedures allow researchers to study romantic dynamics dyadically, with regard to potentially meaningful relationships, and with strong external validity. This article highlights the strengths and promise of speed-dating procedures, reviews some of their most exciting contributions to our understanding of the social psyche, and illustrates how scholars can employ speed-dating and its straightforward variants to study topics relevant to diverse subfields of psychological science.

Tuesday, July 08, 2008

On the heels of the open access debate instigated by Declan Butler's recent article in Nature, and after the canonization of St. Logothetis by a number of neurobloggers (this one included), David Poeppel has informed us that the Nature Publishing Group has started an exciting new journal, Nature People. And the first featured science celebrity is none other than Dr. Logothetis himself. Dr. Poeppel offers his opinion on the fledgling publication:

I recommend as reading a piece on the sociology of science and scientific conduct that just came out in Nature. The article tells the embarrassing saga of a dataset acquired by two former Logothetis trainees and published in the journal Human Brain Mapping this past May.

. . . .

The two authors should not have proceeded to the publication stage without involving the PI much more closely, given the origin of the data; the PI should show more perspective and coolitude and chillaxity (both closely related to Stephen Colbert's truthiness) -- and write a calm and carefully argued response, if the stakes are really that high; the journal Human Brain Mapping should have allowed time for a published response, given that that is not uncommon for journals...; Nature should not write about this -- unless this is NPG's new Nature People (nobody wins with this type of hype, I bet).

The director of a top laboratory in Germany has charged that two of his former research students took data from his laboratory without his permission and published scientifically incorrect interpretations of them against his advice.

Neuroscientist Nikos Logothetis (pictured), of the Max Planck Institute for Biological Cybernetics in Tübingen, further claims that the journal involved, Human Brain Mapping, acted incorrectly by publishing the paper after he told them the data were inappropriate. He says the journal has denied him the right to a timely reply.

One of the two editors-in-chief of Human Brain Mapping, Peter Fox of the University of Texas Health Science Center in San Antonio, told Nature that the paper was correctly refereed, but declined to add details.

Logothetis is furious about the publication of data, which he believes will mislead the field, and about the fact that the authors of the paper allege that he tried to stop them publishing the data for personal reasons.

What about the authors?

Shmuel and Leopard [sic] issued a statement to Nature in which they say: “We are confident, and rigorous peer review agreed, that the data we collected are appropriate for studying spontaneous activity and the resting state in the brain. We stand by the conclusions we made in our paper.”

Here's the link to the paper, so you can read it and decide for yourself.

The incident does raise serious issues of data "ownership" (Logothetis granted the duo permission to use the data, but reneged at a later date), authorship (the first author allegedly "invited Logothetis to join as third author, telling him that the paper had already been accepted for publication and would appear online in a few days"), and "jurisdiction" (What's the proper role of the research institution? Did Logothetis have the right to tell Peter Fox how to run his journal?).

What do you think? How could such a major public imbroglio have been averted?

NEW YORK (AP) — Joey Chestnut achieved frankfurter immortality Friday, outdueling his celebrated Japanese rival in an epic hot-dog eating contest that pushed both of the gluttonous gladiators to the brink.

In a seesaw struggle for the ages, Chestnut and Takeru Kobayashi each consumed an eye-popping 59 hot dogs in 10 minutes, forcing an unprecedented showdown that tested the very depths of their distended stomachs.

Under the glare of ESPN and facing a boisterous and sweaty crowd of thousands on Coney Island, Chestnut, the reigning champ, and Kobayashi, the six-time title holder, were forced to gobble down another five hot dogs in overtime.

"These competitive eaters are an interesting group of people who seem to have abilities that many people in the normal population don't have," David Metz, a gastroenterologist at University of Pennsylvania in Philadelphia, tells DBIS.

Many competitive eaters train for an event by chugging gallons of water to help stretch the stomach. Others eat large quantities of low-calorie, high-fiber foods, like cabbage, that stay in the stomach longer before breaking down. Doctors believe expert eaters may have the ability to keep eating after they're full by suppressing the stomach signals to the brain that indicate it's satisfied.

We speculate that professional speed eaters eventually may develop morbid obesity, profound gastroparesis, intractable nausea and vomiting, and even the need for a gastrectomy. Despite its growing popularity, competitive speed eating is a potentially self-destructive form of behavior.

The purpose of our investigation was to assess the stomachs of a world-class speed-eating champion and of a control subject during a speed-eating test in our gastrointestinal fluoroscopy suite to determine how competitive speed eaters are able to eat so much so fast.

The Wall Street Journal Health Blog also describes the paper (complete with gastrointestinal fluoroscopic images) and interviews radiologist Marc Levine. The study compared "an unnamed champion eater, ranked in the top 10 in the world, who was 29 years old, 5′10″ tall and weighed 165 pounds" to "just some guy who 'had a hearty appetite' (35 years old, 6′2″, 201 pounds)."

The regular guy went first, and stopped after seven dogs... Using fluoroscopy, an x-ray that gives a real-time view of what’s going on inside the body, the doctors saw what you’d expect: His stomach was indeed full of hot dogs and hadn’t stretched much from its original size.

Then they looked at the competitive eater. First, they noticed that his empty stomach showed virtually no peristalsis, the normal squeezing motion that helps the stomach break down food. He started eating hot dogs and his stomach got bigger and bigger. Ten minutes in, he’d eaten 36 dogs. He said he didn’t feel full, but the researchers told him they’d seen enough.

“His stomach now appeared as a massively distended, foodfilled sac occupying most of the upper abdomen, with little or no gastric peristalsis,” they wrote in their paper. Levine said the stomach was like no healthy stomach he’d seen in his 30-year career. He compared it to a “giant balloon that looks like it has no limit.” The eater’s previously flat belly swelled out as if he were pregnant.

Friday, July 04, 2008

You may have read by now the official lie about this treatment, which is that it “simulates” the feeling of drowning. This is not the case. You feel that you are drowning because you are drowning—or, rather, being drowned, albeit slowly and under controlled conditions and at the mercy (or otherwise) of those who are applying the pressure.

In September 2002, four members of Congress met in secret for a first look at a unique CIA program designed to wring vital information from reticent terrorism suspects in U.S. custody. For more than an hour, the bipartisan group ... was given a virtual tour of the CIA's overseas detention sites and the harsh techniques interrogators had devised to try to make their prisoners talk.

Among the techniques described, said two officials present, was waterboarding, a practice that years later would be condemned as torture by Democrats and some Republicans on Capitol Hill. But on that day, no objections were raised. Instead, at least two lawmakers in the room asked the CIA to push harder, two U.S. officials said.

However, in 2004, a quiet hero emerged from a most unlikely place -- from within the Bush Administration -- as described last year by Amy Goodman:

In a remarkable demonstration of commitment to his job, former acting Assistant Attorney General Daniel Levin, according to ABC News, underwent waterboarding when tasked by the White House to rework its official position on torture in 2004. Concluding that waterboarding is torture, he was forced out of his job.

What more can be added to the debate over U.S. interrogation methods, and whether waterboarding is torture? Try firsthand experience. The author undergoes the controversial drowning technique, at the hands of men who once trained American soldiers to resist—not inflict—it.

How does it feel to be “aggressively interrogated”? Christopher Hitchens found out for himself, submitting to a brutal waterboarding session in an effort to understand the human cost of America’s use of harsh tactics at Guantánamo and elsewhere.

"Well, then, if waterboarding does not constitute torture, then there is no such thing as torture."

However, he goes on to appears to contradict himself just a couple of paragraphs later.

ADDENDUM: He presents the arguments on both sides of the debate "at their strongest" but has praise for those who endorse torture:

The team who agreed to give me a hard time in the woods of North Carolina belong to a highly honorable group. This group regards itself as out on the front line in defense of a society that is too spoiled and too ungrateful to appreciate those solid, underpaid volunteers who guard us while we sleep. ... As they have just tried to demonstrate to me, a man who has been waterboarded may well emerge from the experience a bit shaky, but he is in a mood to surrender the relevant information and is unmarked and undamaged and indeed ready for another bout in quite a short time. When contrasted to actual torture, waterboarding is more like foreplay. No thumbscrew, no pincers, no electrodes, no rack. Can one say this of those who have been captured by the tormentors and murderers of (say) Daniel Pearl? On this analysis, any call to indict the United States for torture is therefore a lame and diseased attempt to arrive at a moral equivalence between those who defend civilization and those who exploit its freedoms to hollow it out, and ultimately to bring it down. I myself do not trust anybody who does not clearly understand this viewpoint.

Maybe if Hitchens were forced to endure the experience of actually drowning for more than a few seconds, again and again and again, he just might change his mind. He is certainly not convinced by the words of Malcolm Nance, a former master instructor and chief of training at the U.S. Navy Survival, Evasion, Resistance and Escape School. Hitchens again:

I passed one of the most dramatic evenings of my life listening to his cold but enraged denunciation of the adoption of waterboarding by the United States. The argument goes like this:

1. Waterboarding is a deliberate torture technique and has been prosecuted as such by our judicial arm when perpetrated by others.

2. If we allow it and justify it, we cannot complain if it is employed in the future by other regimes on captive U.S. citizens. It is a method of putting American prisoners in harm’s way.

3. It may be a means of extracting information, but it is also a means of extracting junk information. ...

4. It opens a door that cannot be closed. Once you have posed the notorious “ticking bomb” question, and once you assume that you are in the right, what will you not do? Waterboarding not getting results fast enough? The terrorist’s clock still ticking? Well, then, bring on the thumbscrews and the pincers and the electrodes and the rack.

Functional MRI is an excellent tool for formulating intelligent, data-based hypotheses, but only in certain special cases can it be really useful for unambiguously selecting one of them, or for explaining the detailed neural mechanisms underlying the studied cognitive capacities. In the vast majority of cases, it is the combination of fMRI with other techniques and the parallel use of animal models that will be the most effective strategy for understanding brain function.

The 14 page Supplementary Information is comprehensive as well, covering topics such as MRI and fMRI Principles, Single and Multiple Unit Activity vs. Local Field Potentials, and Spatial Specificity, all documented by 112 references.

Finally, Logothetis has some sharp words not only for the fMRI pollyannas among us, but also for the naysayers (lest we get too dismissive):

Its popular fascination is reflected in countless articles in the press speculating on potential applications, and seeming to indicate that with fMRI we can read minds better than direct tests of behaviour itself. Unsurprisingly, criticism has been just as vigorous, both among scientists and the public. In fact, fMRI is not and will never be a mind reader, as some of the proponents of decoding-based methods suggest, nor is it a worthless and non-informative 'neophrenology' that is condemned to fail, as has been occasionally argued.

But what I really want to discuss here is a News Focus item in the 13 June 2008 issue of Science.

It's easy to propose that allocations of scarce resources should provide the greatest benefit to a group as a whole and be as fair as possible to individual members of the group, but what should be done when both aims cannot be optimized simultaneously? Hsu et al. (p. 1092... see the 9 May news story by Miller) use functional brain imaging, not to resolve these dilemmas, but to probe the underlying cognitive and emotional processes supporting one view (favoring equity, for instance) versus the other (maximizing the good). Brain regions involved in encoding reward relate also to calculations of total benefit, whereas the balancing of equity and utility seems to be the province of the insula, which connects with emotion-processing neural systems. Thus, judgments of fairness derive from emotion-based preferences, rather than those of pure reason.

[The insula]'s a pretty large area. Besides being crowned the "seat of emotional reactions" (whatever that means), portions of the insula have been associated with interoceptive awareness, visceral sensation, pain, autonomic control, and taste, among other things... a lot of other things. Do a search of the BrainMap database using just two of the many insular foci reported by the Caltech researchers and you'll see activations related to action execution, speech, attention, language, explicit memory, working memory, and audition.

The 9 May news story by Miller mentions the 2001 Science paper on moral judgment and emotion (Greene et al., 2001).4 In that paper, the authors

reported that the medial frontal gyrus and other brain regions linked to emotion become more active when people contemplate "personal" moral dilemmas--such as shoving the man onto the trolley tracks or removing a man's organs against his will to save five transplant recipients--compared with when they weigh impersonal moral dilemmas--such as flipping a switch to save the workers or declaring bogus business expenses on a tax return.

Besides the medial frontal gyrus [BA 9/10, which did not replicate in Experiement 2], what were these other brain regions linked to emotion? Did they include the insula? No, they did not. They included the posterior cingulate gyrus (which has some grounding in reality) and the L and R angular gyri (which does not5).

Ironically, the 13 June story by Miller interviewed Russell Poldrack on the infamous New York Times Op-Ed piece (and the moral judgment paper):

Neuroimagers gone wild

What irked Poldrack and others most about the Times's op-ed was the way the authors inferred particular mental states from the activation of particular brain regions: Activity in the anterior cingulate cortex indicated mixed feelings about Hillary Clinton, for example, whereas amygdala activation indicated "voter anxiety" about Republican candidate Mitt Romney.

. . .

He and others argue that reverse inferences are particularly common in newer fields such as social cognitive neuroscience and neuroeconomics (not to mention neuropolitics), fields in which researchers are still trying to identify the cognitive processes underlying the behaviors they study. As an example, Poldrack points to a widely cited paper that used fMRI to investigate brain activity in subjects pondering moral dilemmas (Science, 14 September 2001, p. 2105); some of the brain regions that lit up had been linked in previous studies to emotional and "rational" cognitive processes, and the authors concluded that these two types of processes are active, to different degrees, in different types of moral judgments. But the strength of such arguments hinges on how specifically a given brain area is linked to a given mental process. Poldrack points out, for example, that some of the "emotional" brain regions in the morality study have also been connected to memory and language--a caveat that is rarely mentioned in media coverage of the work (Science, 9 May, p. 734).

So it appears that Science isn't exactly following its own advice... Granted, 14 September 2001 was a while ago, but 23 May 2008 was not.

Footnotes

1Logothetis views

the modular organization of many brain systems as a well established fact, and discuss only how far fMRI can go in revealing the neuronal mechanisms of behaviour by mapping different system modules and their dynamic inter-relationships. In this context the term module captures the classical local neuronal circuits repeated iteratively within a structure (for example, the columns or swirling, slab-like tangential arrangements of the neocortex), as well as the entities within which modules might be grouped by sets of dominating external connections.

2Pure insertion

asserts that a single cognitive process can be inserted into a task without affecting the remainder, an assumption that all too often is not tenable... Even if an experimental design could satisfy this assumption at the cognitive level, the assumption would be condemned to fail at the level of its neuronal instantiation owing to the highly nonlinear nature of most brain processes. To overcome this kind of problem and ensure better interpretation of the neuroimaging data it is necessary to perform a detailed task analysis to determine subtraction components and their interactions. Yet most neuroimaging studies provide no formal task analysis that would ensure that the particular cognitive process of interest is indeed being isolated by the subtraction.

3In adaptation designs,

a stimulus is presented repeatedly with the expectation that it will eventually induce response adaptation in neurons selective for its various properties. In general, repetition of an identical stimulus does indeed produce a reduction in the fMRI signal. After adaptation, the subject is presented with a stimulus that is varied along one dimension (for example, the direction of a moving pattern or the view of a human face) and the possibility of a response rebound is examined. If the underlying neural representation is insensitive to the changes in the stimulus then the fMRI signal will be reduced, similar to the reduction produced by the repetition of identical stimuli. Alternatively, if the neurons are sensitive to the transformation, the signal will show a clear rebound to its original, pre-adaptation level.

You are in hospital lounge waiting to visit a sick friend. A young man sitting next to you explains that his father is very ill. The doctors believe that he has a week to live at most. He explains further that his father has a substantial life insurance policy that expires at midnight.

If his father dies before midnight, this young man will receive a very large sum of money. He says that the money would mean a great deal to him and that no good will come from his father's living a few more days. He offers you half a million dollars to go up to his father's room and smother his father with a pillow.

Is it appropriate for you to kill this man's father in order to get money for yourself and this young man?

5 If you read the 17 abstracts carefully, you'll note that activation of the angular gyrus was mostly associated with things like cognition and mathematical processing, not emotion. Compare that search to the 170 papers in PubMed related to posterior cingulate and emotion.

Wednesday, July 02, 2008

"Running fast is like the exact opposite of death - it's an example of aliveness."

Work No. 850 centres on a simple idea: that a person will run as fast as they can every thirty seconds through the gallery. Each run is followed by an equivalent pause, like a musical rest, during which the grand Neoclassical gallery is empty.

This work celebrates physicality and the human spirit. Creed has instructed the runners to sprint as if their lives depended on it. Bringing together people from different backgrounds from all over London, Work No. 850 presents the beauty of human movement in its purest form, a recurring yet infinitely variable line drawn between two points.

When Martin Creed won the Turner Prize for exhibiting a light bulb going on and off, critics said conceptual art had finally run out of puff.
With his latest masterpiece, he is out to prove them wrong.
The artist's new installation, Work No 850, consists of a runner sprinting the length of Tate Britain's neo-classical sculpture galleries.
Every 30 seconds between 10am and 6pm, an athlete will make the 86-metre dash from one end to the other - for four months.

Tuesday, July 01, 2008

COLLEGE STATION -- A cold slice of watermelon has long been a Fourth of July holiday staple. But according to recent studies, the juicy fruit may be better suited for Valentine's Day.

That's because scientists say watermelon has ingredients that deliver Viagra-like effects to the body's blood vessels and may even increase libido.

Does the press release cite any papers proving that watermelon is an aphrodisiac? Need I even ask this question? Try typing watermelon libido in PubMed. No items found.Same result for watermelon aphrodisiac. And "citrullus" was automatically included as a search term.

Beneficial ingredients in watermelon and other fruits and vegetables are known as phyto-nutrients, naturally occurring compounds that are bioactive, or able to react with the human body to trigger healthy reactions, [Dr. Bhimu] Patil said.

In watermelons, these include lycopene, beta carotene and the rising star among its phyto-nutrients – citrulline – whose beneficial functions are now being unraveled. Among them is the ability to relax blood vessels, much like Viagra does.

Scientists know that when watermelon is consumed, citrulline is converted to arginine through certain enzymes. Arginine is an amino acid that works wonders on the heart and circulation system and maintains a good immune system, Patil said.

"The citrulline-arginine relationship helps heart health, the immune system and may prove to be very helpful for those who suffer from obesity and type 2 diabetes," said Patil. "Arginine boosts nitric oxide, which relaxes blood vessels, the same basic effect that Viagra has, to treat erectile dysfunction and maybe even prevent it."

...some supplement companies are marketing L-citruilline--a by-product of the arginine-to-nitric oxide pathway--as a substance to increase nitric oxide synthesis in vascular endothelial cells. Although safe, citrulline does not directly convert to nitric oxide, but instead is recycled to L-arginine (an ATP-dependent process), which then converts to nitric oxide. Ferid Murad, MD, PhD, Nobel-prize winner for his research on nitric oxide, has said the use of L-citrulline to increase nitric oxide is only marginally effective.

About Me

Born in West Virginia in 1980, The Neurocritic embarked upon a roadtrip across America at the age of thirteen with his mother. She abandoned him when they reached San Francisco and The Neurocritic descended into a spiral of drug abuse and prostitution. At fifteen, The Neurocritic's psychiatrist encouraged him to start writing as a form of therapy.